"Xbox LIVE should be back up and running. Thank you for your patience. Game on!" a member of the Xbox Support crew tweeted at about 1:30 p.m. PT.
CNET employees who are subscribers have confirmed that have been able to log on to their account, meaning they can access at least part of the service.
The gaming service was experiencing "difficulties" this morning, with users taking to Twitter to complain around 8:30 a.m. PT. In all, it was down for about five hours.
A Microsoft representative didn't offer details on what caused the disruption, but said techs got on it quickly and he doesn't expect any more issues.
"Xbox LIVE was experiencing temporary service issues with signing onto Xbox LIVE from the Xbox 360 console and from Xbox.com," a statement from the company read. "Our engineering teams worked quickly to fix the problem and the service is online and fully operational."
This story was updated at 1:52 p.m. PT with comment from Microsoft.
CNET's Don Reisinger contributed to this report.